What modem did they give you?
Also, what speeds are you currently getting?
Could also be a problem with the phone lines / location of the modem.
Make sure the modem is as close to the main box as possible (you basically want only 1 split from the main line to the modem, and then to the rest of the house).
Both the speed and reliability of a DSL connection can be affected by numerous factors, including:
Your distance from the phone company's central office or remote DSLAM, measured in feet of wire (not the driving distance or the distance "as the crow flies"). The greater the distance, the more problems you're likely to encounter; and if the distance is more than 18,000 feet, you may as well forget about DSL.
The quality of the "public" phone lines. Old or poor-quality wiring between your location and the Central Office or DSLAM can severely impact DSL speed and reliability.
The quality of your telephone wiring (that is, the wiring inside your home or business). Obsolete or poor-quality wiring, wiring that has been split or spliced, or wiring that is shared with devices such as alarm system transponders can adversely affect your DSL performance.
The total number of phone devices on the line. Every phone, fax machine, DSL filter, or other device on the phone line carrying the DSL signal adds a little capacitance and voltage drop to the circuit, which in turn can reduce the speed and stability of the DSL service.
Unfortunately, there's nothing we can do about the first two problems.
DSL Optimization: Improving DSL Speed and Stability
If your DSL service is suffering due to deficiencies in you own wiring, we can help. Our DSL optimization service consists of the following: (Click here for a helpful, explanatory diagram that will open in a new window so you can keep reading.)
We install a DSL/POTS splitter immediately downstream of the phone company's NIB (the Network Interace Box, or the place where the public phone lines are connected to the wiring in your building). This is usually located on an outside wall, in the basement, or in a mechanical room.
We run a new, dedicated line (often called a "home run") from the splitter to the DSL modem, using Category 5e UTP cable. This reduces overall capacitance and improves signal quality. (Exception: If a suitable, unused line already exists between the two points, then the new line may not be needed.)
If possible, we relocate the DSL modem to a place as close to the NIB as possible, and run Ethernet cable from the modem to the computer or router. Ethernet is much less susceptible to degradation over distance than a DSL signal is.
Basically you want to split the phone line where it comes into your home, and have one feed the rest of the house and the other straight to the modem.
*Quotes ripped from some company's site. Good advice for DSL subscribers though...